# Trade Interaction: Marginal Effects of Z1

Interaction model: savings = ... + -74.19*Z1 + 1.9323*Z1*trade + ...

## Marginal Effect of Z1 at Different Trade Openness Levels

| Trade Openness | Percentile | Marginal Effect of Z1 | Approx SE | Sig |
|---|---|---|---|---|
| 50.8 | 25th | 23.90 | 33.30 |  (p=0.4730) |
| 73.9 | Median | 68.58 | 36.85 | * (p=0.0628) |
| 103.9 | 75th | 126.53 | 42.65 | *** (p=0.0030) |

## Regression Details

N = 4,285, R2 = 0.172

| Variable | Coef | SE |
|---|---|---|
| Z_1 | -74.1922 | 29.7700 |
| Z_2 | 13.7292 | 4.4955 |
| Z_3 | -0.6269 | 0.1831 |
| rgdp_growth | 0.3697 | 0.0175 |
| kaopen | -0.2707 | 0.2232 |
| nfa_gdp_lag | 0.8499 | 0.2502 |
| Z_1_x_trade | 1.9323 | 0.2940 |
| Z_2_x_trade | -0.2930 | 0.0441 |
| Z_3_x_trade | 0.0119 | 0.0018 |

*Marginal effect = beta_Z1 + beta_(Z1*trade) * trade_openness. SEs approximate (diagonal of vcov only, ignoring covariance — conservative). Trade openness = (exports + imports) / GDP.*